My electrolysis tank is pretty simple, and on a much smaller scale than Mht's. I bought a plastic tub for $15. I drilled a couple of holes near the ends of a wooden stake to hold my anode(s), and screwed a (conductive) hook through the center to hang or wire the cathode.
The cathode is the NEGATIVE, the anode is the POSITIVE. My anodes are rebar. My power supply began as a 12V smart charger. You can see the charger leads hooked up to the hook (Neg) and the rebar (Pos) in this first photo, but the smart charger tried to out-smart me - it faulted after about ten minutes when hooked up to the e-tank directly.
So to get around the charger fault, I put a 12V battery between the charger and the e-tank (charger to battery, and jumper cables from the battery to the cathode/anode). I use 2-3 heaping cups of Washing Soda to make the water conductive (same as Mht). I put the washing soda in a jug, fill the jug with hot water and shake vigorously to make sure the washing soda is completely dissolved. That's why the water in the first photo looks so cloudy. The part submerged in the photo is a final drive, sitting on the bottom of the tub and a piece of mechanic's wire wiring it to the hook. The anode (rebar) should never touch the part being "cooked". Also - a member here (Rudi) is a fervent believer in adding TSP (trisodium phosphate) to the water to prevent flash rust after the part is removed from the tank. I added a cup of TSP to my water, and I think it definitely helps. Thanks Rudi!
The second photo shows the jumper cables from the battery (green leads). I made a little "Faraday Cage" and tried some rusty bolts in with the final drive. Not so great on straight rust, but really good results blowing off paint.
One final important tip -
the CLEANER the anode, the better the reaction. And by clean I mean bare metal. I use only one rebar anode at a time, and switch it for a clean rebar about every 12 hours. I rinse off the old rebar (the sludge which forms during electrolysis rinses right off), let the rebar dry and the
WIRE WHEEL the REBAR, back down to bare metal. This is very important.
Another thing I do is run the tank using just the battery during the day (with a fresh anode). Then in the evening, replace the anode again and plug in the charger (to recharge the battery overnight). This seems to work well.
Any questions, let me know. I've been using the tank for almost three weeks now. The water is pretty nasty, but it still bubbles nicely, especially when I put a clean anode in. I do know my wife is pretty impressed!
Reg